The field of the invention is collapsible furniture.
Folding chairs are relatively popular, in part because they can be stored at considerably reduced space requirements when compared to non-folding chairs. Exemplary folding chairs with solid arm rests and seat support rods are described in U.S. Pat. No. 4,613,185 to Marchesini et al. (Sep. 23, 1986), U.S. Pat. No. 5,899,525 to Tseng (May 4, 1999), U.S. Pat. No. 5,947,553 to Tseng (Sep. 7, 1999), and U.S. Pat. No. 6,062,639 to Hill (May 16, 2000), all of which are incorporated by reference herein.
Nevertheless, previously known folding chairs still take up a relatively large space when folded, since the dimension of the folding chair is generally reduced only along one space coordinate (e.g., reduced length). To further reduce the space requirement, collapsible chairs have been developed in which further size reduction is achieved by folding the chair along at least two space coordinates (e.g., length and width). Various collapsing chairs are known in the art.
For example, Sparkes describes in U.S. Pat. No. Des 247,618 (Mar. 28, 1978) a collapsible stroller with solid armrests and seat support rods that is first folded in a front to back motion and then folded in a side-to-side motion. Although Sparkes"" stroller provides substantial space saving over non-collapsible strollers, the collapsing is relatively cumbersome since both halves of the chair have to be rotated relative to each other. Improved collapsibility can be achieved by including a detachable connector element into a structure that couples foldable halves of the stroller as described in U.S. Pat. No. 4,317,581 to Kassai (Mar. 2, 1982). Uncoupling of the detachable element advantageously simplifies side-to-side folding of the stroller. However, Kassai""s stroller nevertheless requires at least two folding operations to collapse the stroller.
To avoid at least some of the problems associated with multiple operations of collapsible chairs, Mann describes in U.S. Pat. No. 5,058,950 (Oct. 22, 1991) the use of hinges in both armrests and seat support rods. Mann""s chair can be collapsed in a single side-to-side and front-to-back motion, however, the hinges in the armrests may be uncomfortable for at least some of the users. Moreover, due to the particular configuration of movable elements in the chair, front and back seat support rods are perpendicular to the legs of a person sitting in the chair, which will likely restrict blood flow in the legs of almost all users over a prolonged period.
Although there are various collapsible chairs with solid armrests known in the art, all or almost all of them suffer from one or more disadvantages. Therefore, there is a need to provide improved methods and apparatus for collapsible chairs with solid armrests.
The present invention is directed to a collapsible chair that can be collapsed in a single motion, wherein the chair includes solid arm rests and a (preferably) tensioned seat coupled to a pair of seat support rods. In particular, the collapsible chair has a pair of front legs, a pair of rear legs, a pair of back support rods, a pair of seat support rods, and a pair of solid arm rests. Contemplated chairs further comprise a first pair of cross braces that couple the pair of front legs to the pair of seat support rods, and a second pair of cross braces that couple the pair of rear legs to the pair of back support rods, and at least one of the rear legs is rotatably coupled to at least one of the seat support rods. At least one of the arm rests and at least one of the seat support rods are rotatably coupled to at least one of the back support rods and at least one of the front legs in a manner such that the chair collapses in a single movement in which the front legs approximate each other when the seat support rods pivots towards the back support rods.
In one aspect of the inventive subject matter, at least one of the seat support rods is further rotatably coupled to at least one of the back support rods, and it is further preferred that contemplated chairs further comprise a connector that connects at least one of the rear legs on one side of the chair with at least one of the back support rods at the same side of the chair.
In another aspect of the inventive subject matter, contemplated chairs comprise a backrest coupled to the back support rods, and a seat coupled to the pair of seat support rods, and it is particularly preferred that the backrest is continuous with the seat (preferably a tensioned seat). With respect to the materials it is contemplated that the backrest and/or the seat comprise a weather resistant fabric (e.g., Nylon), and that at least one of the pair of front legs, rear legs, seat support rods, back support rods, and first and second cross braces is manufactured from aluminum.
In a further aspect of the inventive subject matter, a method of imparting collapsibility into a chair comprise one step in which a pair of front legs, a pair of rear legs, a pair of back support rods, a pair of seat support rods, and a pair of solid arm rests are provided. In a further step, the pair of front legs are coupled to the pair of seat support rods with a first cross brace, and the pair of rear legs is coupled to the pair of back support rods via a second cross brace. In a further step, at least one of the arm rests and at least one of the seat support rods are rotatably coupled to at least one of the back support rods and at least one of the front legs in a manner such that the chair collapses in a single movement in which the front legs approximate each other when the seat support rods pivots towards the back support rods.